Are we just kidding ourselves with our chemical water treatments?

In the CDC article from OP, combination filtration and disinfection has a very high effectiveness on everything.

Long ago I was sick from bad water and it wasn't fun. Very keen to avoid that experience again. The water at the time was pumped straight from a dam, no treatment. Long drought, then rains washed all sorts of stuff into the dam. At the time, I naively thought all towns had water treatment. In Australia, small towns may not. I've had to treat "town water". Also, some towns have several different water sources. St George, QLD for example has three: rain water, bore water and water pumped straight from the river. So you really need to check which tap you fill up from. The locals list them as: Drink, wash, water the garden.

I filter first, than use chlorine. The chlorine then stays in my drinking containers – helping keep them clean.

I've read that bacteria in water clump up – either together or to other particles in the water. http://www.who.int/water_sanitation_health/resourcesquality/wqmchap10.pdf

So I figure that filtering first removes these clumps. Removing organic matter improves the chlorine application also; read the instructions about how very dirty water may require more than the standard dosage.

I put a lot of time into researching the likely water bugs, and it seemed to me, that the larger sized bugs which are easy to filter are the ones most resistant to chlorine and iodine. The smaller stuff, harder to filter, dies quicker with chlorine or iodine.

Currently using a Sawyer filter in a gravity system.

Using Katadyn Micropur, which list the treatment times as "Contact Time: 30 min for bacteria and viruses, 2 h for Giardia in clear water." http://www.katadyn.com/en/katadyn-products/products/katadynshopconnect/katadyn-micropur-micropur-forte/micropur-forte-mf-1t-enplczhuru/
Since I've filtered the water – no giardia. So 30 minutes is all I need. I can wait that long.

I use chlorine over iodine as its impossible to poison yourself with too much chlorine. The water smells like a pool, and your not going to drink it. Leave it sit, aerate it, or add a vitamin C tablet to neutralize the chlorine (after the 30 minutes) and your good to go.

If my filter fails, I can "Super Chlorinate". Add excess chlorine, wait, then neutralise. (I carry other chlorine besides the micropur tablets as well. Re-supply in parts of Australia is measured in weeks.) Chlorine can be mixed up for cleaning.

Iodine – has no indicator you have too much in the water. It is more problematic for your health if you have too much. I'd rather not have to worry about accidental over dosages.

Cause, when the only water about is the colour of dirt, the cows, pigs, roos and other animals have been stirring it up, urinating and defecating in it, filtering and or tablets is a waste of time. Boil it.

I've seen people drinking straight from questionable streams without purifying. I think it is unwise. But it's up to them. For me, travelling solo in remote areas, being sick from bad water could turn a lovely journey into an unpleasant struggle. Depending how sick I get, it could turn life threatening and require me to be rescued. The effort to filter then disinfect outweighs the consequences of not doing it. I'm not going to risk it.

Either no one needs to treat, or chems work as good as filtering for what is required.

There can be no other way to rationally evaluate the fact that no one seems to get sick who treats water with AM.

M B,

"The proof is in the results. People simply aren't getting sick. But you would propose we aren't doing any good?"

Where is your control group? Without one, we cannot evaluate the effectiveness of any treatment because we can't compare it to a non-treatment (control) group.

There can be no other way to rationally evaluate the fact that no one seems to get sick who treats water with AM.

How do you know no one gets sick who treats water with AM? Where is your data? Your use of the word "seems" is telling here. Basing assumptions on casual observation of, say, the BPL forum, doesn't cut the mustard for me. I want to see data, and from what I can tell, there is none.

I believe McNett when they say that AquaMira, when used in a certain way, will kill 99.9% of viruses, bacteria, Giardia, Crypto, etc. Those numbers come from very controlled settings though. In particular, in my experience, I often treat water that is quite cold and sometimes has sediments in it, and I almost never wait 4 hours before drinking the water. How much does this affect the efficacy of the treatment in the real world?

"Either no one needs to treat, or chems work as good as filtering for what is required."

Perhaps! This is exactly the point of this post! Trying to get to the bottom of this. I have just found very little data on it. For example, we really don't know how many people get sick when they treat, or don't treat their water in the backcountry. We also don't know how this varies from region to region, etc.

I totally agree with your attitude of being skeptical of anecdotal accounts.

I don't have time to cite the studies I'm thinking of right now, but I can at a later date if you like.

There are no definitive breakdowns of the number of people getting sick vs not getting sick treating/not treating with various methods in the backcountry.

The largest study of which I'm aware DID show that each of the following had a significant impact on gastrointestinal health in backpackers: treating water, washing dishes, washing hands.

Additionally, NOLS, who might have better real-world data than anyone, has achieved a remarkable record, at least an order of magnitude better than other hikers, keeping people healthy stomach-wise by stressing good practices in all three of the above. Aqua Mira is one of their standard treatment methods.

There are charts showing the effect of contact times of chlorine and chlorine dioxide at a given concentration, PH, and temp.

We know, without any doubt, that there are human pathogens often found in backcountry water and without any doubt, Aqua Mira, used as directed, will kill most of them, even at less than four full hours. The only test I'm aware of concerning hiker's hands showed they had coliforms on them, but not as many at the end of a trip as the beginning. Regardless, clean hands will up our odds of staying healthy.

In a case like this I think it's wise to concentrate on what we do know, rather than on what we don't know.

NOLS is a "group" situation. Individuals is another situation.

In the former, treating dishes and treating hands could be the critical elements.

In the later, assuming we can't "self-innoculate" (really?) treating water is the critical element.

Obtaining sound data for numerous cases of n=1 is the challenge.

The one thing I don't mess around with is water purification. The past few years I have been using CLO2 tablets and I always wait 4 hours. Yes, sometimes I have to carry more water than I would like as part of my water strategy. Plus I don't trust the so-called back country surveys of hikers.

Last week I got into a bad situation, ran out of water earlier than planned due to difficult terrain. By the time I got to a set of spring fed desert pools I was in bad shape. Ended up boiling a gallon of water, which was not cool and refreshing, but it was safe to drink.

The main reason I bring a wrist watch is to monitor water purification times. It is more important to me than cell phones, PLB's and other similar electronics, none of which I use.

Nick, why don't you just carry a filter or a steripen instead of waiting 4 hours?

Justin,

Filters clog from what I have read – never owned one. The Stripen can break, I have read a lot of bad things about them. As matter of fact I once did a hike with some guys and two Steripens wouldn't work!

In the mountains I normally only drink 2 liters of water during the day, so the most I am ever carrying is 2 liters. If I need more, I add CLO2 4 hours before I will need the water.

In deserts my trips are planned around water sources, usually getting to the next water at the end of the day. Most desert trips I am carrying at least 4 liters of water each morning, unless water is more than a day's distance. No advantage in deserts for filters or Steripens, they weigh more than tablets and there is no such thing as stopping for water when you are thirsty. Prior to 2008 I used iodine for 40 years and boiled questionable water. Iodine kills everything but crypto.

Anyway, I have done this all my life and never got sick. No need to change. There are other things I have changed to save weight.

"There are charts showing the effect of contact times of chlorine and chlorine dioxide at a given concentration, PH, and temp."

Buck,
Could you point me in the directions of these charts? I'm interested to take a look at them for my own edification.

Also, your points about proper personal hygiene, especially hand washing, are good to bring up. Definitely a major route of infections is (poopy) hand to mouth in the backcountry (like everywhere else really).

This one has some charts, discussion

http://www.lenntech.com/processes/disinfection/chemical/disinfectants-chlorine-dioxide.htm

At least compared to chlorine and other chlorine compounds, ClO2 is significantly more effective.

Hi Nick

> I once did a hike with some guys and two Steripens wouldn't work!
But why wouldn't they? User error may be?

The modern Steripens are very effective and very reliable – when used with GOOD batteries. My choice.

Cheers

Hi Roger,

What steripen do you use?

Cheers,

Stephen

Nick, for desert hiking your method makes sense.
I switched away from iodine tablets because hiking in water plentiful areas, within the 30 minutes it takes to treat I could have already passed another water source and I was carrying unnecessary weight. Now I use a sawyer mini usually by screwing it onto my bottle for instant water.

>"the effect of contact times of chlorine and chlorine dioxide at a given concentration, PH, and temp"

Regarding concentration, if you're close to the reference concentration (double the halogen, triple the halogen), the required contact time will be the reciprocal (half as long, a third as long, respectively).

For temperature, being 10C warmer (18F) will take half the time to react. Being 18F colder will take twice as long. Lots of literature and instructions take a typical summer BPing mountain stream temp of 50F. 70F water would need half the contact time. Snowmelt at 32F would need twice the contact time.

pH: I can't be accurate about, off the top of my head.

Ben Tang uses chlorine drops followed by the AM frontier pro, if he hasn't changed his method. He was the first that I saw do it that way.

Hi Stephen

I currently carry a Steripen Adventurer Opti – with brand-name batteries..
I do also have a Steripen Adventurer, but seldom carry it.

I am currently reviewing the new Steripen Classic 3 – an upgraded Adventurer. That will be published in a few months. It may get the nod over the Opti.

If you MUST filter, I would go for the RapidPure these days.

But note that most of the time I am able to use an unpolluted creek anyhow, so I use nothing.

Cheers

Anyone that wants treatment table Google EPA chlorine dioxide treatment, and start reading. One takeaway, is that the recommended protocols are already very CONSERVATIVE, they are for municipal water treatment.

All treatment is based on reduction, not elimination, so the quality of your starting water has a big impact. Unless you drink sewage, you likely won't be getting near the contamination levels used in testing.

"We know, without any doubt, that there are human pathogens often found in backcountry water…"

I do not think that we know this. In the backcountry area I hike (the Sierra Nevada Mountains) I believe that the water is mostly free of unsafe levels of human pathogens. I don't have the ability to test it to know exactly what is in the water, but I believe that most of it has low enough, or no, human pathogens to be safe to drink.

Even with that belief, I filter. I started to improve taste (remove fine sediment) and continue because it is very light, easy and fast to filter (sawyer inline). It is very cheap insurance.

I'm not Roger but I exclusively use a Steripen classic, which has been nearly flawless for me. I had an issue one time where the probes weren't drying in between uses (because I was treating a lot more water than normal) and I got a fault message. I now know to keep the probes dry and have never had a problem again.

"Hi Nick

> I once did a hike with some guys and two Steripens wouldn't work!
But why wouldn't they? User error may be?"

Don't know, I sure couldn't tell them how to use the devices :) — but they had chemicals as back ups. I don't need a back up system.

Since I have never bought a filter or any other device, don't plan to, don't need to research them… I have saved a ton of time to put to more productive use :)

Can't say I have saved more money by not buying all of the above vs using CLO2 tablets, but I buy them in bulk.

At the end of the day we use what works for us, whether it be water purification, food preparation, or other gear.

We have gotten of track of the OP, which is partly my fault. My point was I follow directions on the product. I suppose that is also why a gas stove has never blown up on me :)

I've had two Steripens. The first emitted light but was somewhat faint which I noticed half way through a weeklong trip. I sent it in to Steripen and they replaced it as it was not producing enough UV. The replaced version failed to work after new batteries were installed on the trail at the beginning of a weeklong trip after previously purifying about 20 litres. II used chemicals the remainder of the trip; the pen does appear to work now at home but I really don't trust it. Reading Nicks posts validates that I will be moving back to chemicals exclusively. The Steripen is not worth my frustration based on my experience.

" 'We know, without any doubt, that there are human pathogens often found in backcountry water…'

I do not think that we know this. In the backcountry area I hike (the Sierra Nevada Mountains) I believe that the water is mostly free of unsafe levels of human pathogens. I don't have the ability to test it to know exactly what is in the water, but I believe that most of it has low enough, or no, human pathogens to be safe to drink."

In the oft-quoted Sierra Nevada water quality studies of 20-30 years ago giardia cysts were found in about 30% of water sources. That's only a single pathogen. And a very key point is that the minimum infective dose of giardia is NOT 10 cysts as the famous Rockwell paper claims, but one cyst. That's a big, big difference. http://waterbornepathogens.susana.org/menuprotozoa/giardia [In the Rendtorff study 100% of people got giardia with a 10 cyst dose, to the best of my knowledge no one has ever been tested at the 2-9 cyst level.] I think most people will agree after reading through the EPA studies that giardia IS commonly found in backcountry waters. http://water.epa.gov/action/advisories/drinking/upload/2009_02_03_criteria_humanhealth_microbial_giardiaha.pdf

There is no doubt that a single liter of water will most likely not have enough pathogens to make you sick. But a similar argument can be made for most safety considerations. Most times safety belts will not make a difference, nor will hand washing, safety glasses, hardhats, etc. Sometimes the odds go the other way, like when I "drank smart" in the Sierra and got giardia, first trip.

I did not treat my water until I got Giardia. I am NEVER EVER going there again..I treat my water..I have evolved from filters to the Steripen. That's all I have to say about that…gotta go check out that new Steripen Classic 3 Roger was talking about.

Hi Roger,

Thanks for the info, I have one of the original ones but it seems a bit flakey. I will hold off getting a new one until your review cones out.

Cheers,

Stephen

Anecdotally I've found chemicals have worked for me all over the world including places like India and Cambodia. I only started using chlorine dioxide a few years ago. Before that, all I used was iodine; yes I am now aware that it supposedly doesn't work against crypto although I didn't know it at the time.

I think when possible, time is your friend and it's best to let the chemicals treat it for as long as possible. Certainly less concerning in the Cascades vs a country where they pump raw sewage into the rivers/oceans so there's a larger margin of error back home.

In India, I'd treat two liters of water every night with iodine (it'd be chlorine dioxide now) so it had several hours to kill the bugs. I'd use the first liter in the morning to brush my teeth and pound the rest to kick start my hydration regimen for the day. As soon as I got halfway through the second liter, I'd start treating the third; again, this is to give the chemicals a sufficient amount of time to kill the germs.

Again, this is worst case scenario as there there are bugs in their water typically not found here in the US.

I have a steripen opti that works fine and I've never been sick when using it. I use Surefire CR123 batteries.

My preferred method in the US is a Sawyer filter with chemicals as a back-up.